The landfilling of organic materials leads to the anaerobic
breakdown of these materials into landfill gas. Landfill gas is
primarily composed of methane and, to a lesser but significant
amount, volatile organic compounds (VOC). These gases are
released from the
landfill as fugitive emissions. Methane is a potent greenhouse gas,
which is 72-84 times more potent than CO2 as a
global warming gas.
VOCs react with NOx emissions to form ground-level ozone. NOx is a
common combustion product: flares, boilers, internal combustion
engines, and other combustion processes typically generate NOx
emissions. CARB, in partnership with local, State and federal entities
is
working to address methane and related emissions through implementation
of various
programs such as the Landfill Methane Rule (discussed below), Short-Lived
Climate Pollutant Strategy,
and in the 2017
Climate Change Scoping Plan Update.

Environmental
Justice
Advisory Committee (EJAC) Considerations:

CARB also partners with its EJAC to ensure that
implementation of its
climate
change programs provide tangible benefits, and do not negatively impact
disadvantaged communities (DACs). To assist CARB’s efforts, the EJAC
has
provided recommendations that will guide our efforts as we design and
implement strategies to reduce climate change and health impacts from
industrial, commercial, agricultural and transportation sources. More
information regarding the EJAC and its recommendations, many of which
are related to landfills and organics, can be found here:
http://www.arb.ca.gov/cc/ejac/ejac.htm

U.S. EPA's
Updated Rules to
Regulate Municipal Solid Waste Landfills:

History and Background:

On March 12, 1996, the United States Environmental Protection
Agency (U.S. EPA) promulgated a regulation requiring emission controls
for large municipal solid waste (MSW) landfills (61 Fed. Reg. 9905).
The regulation is entitled “Standards of Performance for Stationary
Sources and Guidelines for Control of Existing Sources: MSW Landfills.”
It includes both New Source Performance Standards (NSPS) that regulate
emissions from new landfills and Emission Guidelines that regulate
emissions from existing landfills. See the U.S. EPA webpage (http://www.epa.gov/stationary-sources-air-pollution/municipal-solid-waste-landfills-new-source-performance-standards)
for more information.

The NSPS was implemented by the districts, who have primary
authority to regulate stationary sources such as landfills in
California. For existing landfills, the regulation required each state
to submit a plan to U.S. EPA which identified how the State intended to
meet the federal requirements contained in these guidelines. California
air districts with affected landfills (in conjunction with CARB)
adopted
rules to implement the Emission Guidelines. These rules were forwarded
to CARB and compiled for inclusion in the State plan. In September
1997,
California submitted its State Plan to implement the guidelines.

2016 Updates to the Federal
Landfill
Rules:

NSPS
On August 29, 2016, U.S. EPA finalized a new subpart under section
111(b) of the Clean Air Act for new, modified and reconstructed
municipal solid waste landfills under 40 CFR Part 60, Subpart XXX
(81 FR 59332) effective October 28, 2016. These
New Source Performance
Standards apply to landfills that commenced construction,
reconstruction or modification after July 17, 2014. The districts will
implement the new NSPS provisions under their stationary
source authority. The existing NSPS (40 CFR part WWW) for MSWs remains
in effect concurrently with the new NSPS.

Emission Guidelines
In a separate, but related action, U.S. EPA also issued updated
emission guidelines for reducing emissions from existing MSW landfills
under section 111(d) of the Clean Air Act. The “Emission Guidelines and
Compliance Timelines for Municipal Solid Waste Landfills” (Emission
Guidelines) (81 FR 59275) (40 CFR Part 60, Subpart Cf), is also
effective October 28, 2016. A link to U.S. EPA's NSPS and
Emission
Guidelines, as well as the EPA database of the existing MSW landfills
can be found below:

CARB's Responsibilities in Response to the Updated
Emission Guidelines

As before, the Emission Guidelines require each state to
submit a
compliance plan to U.S. EPA, which was due by May 30, 2017. On
May 25, 2017, the California Air Resources
Board (CARB or Board) adopted California’s State Plan (see below) to
comply with the
updated federal Emissions Guidelines and the plan was subsequently sent
to U.S. EPA on May 30, 2017.

Federal Reconsideration of Emission Guidelines and
90-day Stay

In response to a
petition filed by industry, U.S. EPA announced the convening
of a
proceeding for reconsideration of the final rule. U.S. EPA
indicated as
part of the reconsideration it would prepare a notice of proposed
rulemaking.
Subsequently on May 31, 2017, U.S. EPA published notice of a
90-day stay of the
Guidelines until August 29, 2017. The Federal
Register notice of U.S. EPA’s 90-day stay of the Emissions Guidelines
is
available at:

Landfill Methane Control
Measure:

The California Air Resources Board (CARB) approved a landfill
regulation which
became effective June 17, 2010 that
reduces emissions of methane, a greenhouse gas, from municipal solid
waste (MSW) landfills. The regulation is a discrete early
action greenhouse gas emission
reduction
measure, as described in the California Global Warming Solutions Act
(“AB 32”). The regulation primarily requires owners and operators of
certain
uncontrolled
MSW landfills to install gas collection and control systems, and
requires existing
and newly installed gas and control systems to operate in an optimal
manner. The regulation allows local air districts to voluntarily enter
into memoranda
of understanding (MOU) with CARB to implement and enforce the
regulation
and to
assess fees to cover costs. This webpage follows the
development, implementation and enforcement of the control measure.

The
landfill implementation guidance document assists owners and operators
in complying with the regulation by providing an overview of regulatory
requirements and discusses various topics related to implementation
and enforcement. This document is subject to periodic
revision,
as necessary.

CARB
staff has developed a Landfill Gas Tool to assist owners and operators
in complying with the landfill regulation. The tool is based
on
the mathematically exact first-order decay model from the 2006 IPCC
guidelines and is designed to estimate the fugitive emissions from a
landfill that does not have a landfill gas collection
system. It
uses the Second Assessment Report (SAR) Global Warming Potential (GWP)
of 21 for methane. It
also includes an estimate of the landfill’s captured gas heating value
(in MMBtu/hr). If you have comments or questions about this
tool
please contact Larry Hunsaker,
Staff Air Pollution Specialist. Landfill
Emissions Tool Version 1.3 [Excel-523 KB]